Valve-gear for engines



No. 654,228. Patented July 24, won.

N. A. CHRISTENSEN.

VALVE GEAR FOR ENGINES.

(A iplication filed Nov. 21, 1898.)

3 Sheets-Shut I.

(No Model.)

No. 654,228. Patented July 24. I900. N. A. CHRISTENSEN. VALVE GEAR FOR ENGINES. (Appl mm filed Nov 211898 a- Sheets-Sheet 2.-

(No Model.)

THE mm virus on Puma-Lima. \vM-umoron n c N0. 654,228. Patented July 24, 1900.

N.- A. IZHHISTENSEN.- VALVE GEAR FOB ENGINES.

(Application filed Nov. 21, 1898.)

No Model.) a Sheets-She9i a.

%M Q I @WUQMY); away. I mum k W UNITED STATES PATENT OFFICE.

nIEL-s A. CHRISTENSEN, or

MILWAUKEE, WISCONSIN.

VALVE-GEAR FORENGINES.

SPECIFICATION forming part of Letters Patent No. 654.228, dated J u1y- 24, 1900. Application filed November 21, 1398. serial No. 696,962. on model.)

To all whom, it may concern.-

Be it known that I, NInLs A. CHRISTENSEN, a subject of the King of Denmark, residing at Milwaukee, in the county of Milwaukee and State of \Vlsconsin, havein vented certain new and useful Improvements in Valve-Gear for Engines, of which the following is a specification, reference being bad to the accompanying drawings, forming a part thereof.

The main objects of my invention are to dispense with the Wrist-plate and the dashpot rods commonly employed in automatic cut-off engines and generally to improve the construction and operation of engines of the class to which my improvements relate.

It consists in certain novel features in the construction and arrangement of parts, as hereinafter particularly described, and pointed out in the claims.

Inthe accompanying drawings like letters designate the same parts in the several fig-- ures.

Figure 1 is a front or side elevation and partial vertical section on the line 1 1, Fig. 2, of the valve-gear associated with one of the steam-valves of an engine embodying myinvention. Fig. 2 is a vertical section on the line 2 2, Fig. 1, cutting the valve-gear lengthwise of the valve-stein. Fig. 3 is a horizontal section on the line 3 3, Fig. 1. Fig. 4 is a vertical section on the line 4 4, Fig. 2, cutting the cut-off cam transversely to the val vestem. Fig. 5 is a vertical cross-section on the line 5 5, Fig. 3. Fig. 6 is asimilar section on the line 6 6, Fig. 3. Fig. 7 is a side elevation of a portion of an engine to which my inrproved valve-gear is applied, showing the manner of operating both the steam and exhaust valves by a single eccentric in engines wherein the latest cut-off occurs at about half-stroke; and Fig. 8 is a similar view showing the manner of operating the steam and exhaust valves by separate eccentrics in engines designed to cut off up to full stroke.

Referring to Fig. 7 of the drawings, A des ignates the cylinder ofan engine, B the piston-rod, and O the crank-shaft. D is the cocentric by which in this case both the steam and the exhaust valves are operated. It is connected by a rod cl With a rocker-arm E, which inturn is connected by a rod 6 with the valve-opening lever-arm of the steamvalve at the crank end of the cylinder, the two lever-arms for opening the steam-valves being connected with each other by a rod 6 and each connected by a rodf with an arm F on the stem of the exhaust-valve at the same end of the cylinder.

G is a T-lever one arm oi which is connected by a rod 9 with the governor (which is not shown) in the usual way, the othertwo arms being connected by rods g g with the cut-off cams, as hereinafter explained. Referring to Figs. 1 to 6, inclusive, showing the valve-gearassociaied with each of the steam-valves, H is the oscillating'stem of one of the steam-valves, provided atitsinner end with a T-head, which engages with the steam-valve I, as shown in lig. 2.

J is the bonnet, attached to the engine-cylinder A and formed with a cylindrical extension or bearingj, through which the valvestem loosely passes, and with a flange or shoulder] at the inner end of said extension.

K is the valve-closing lever, corresponding in function with the drop-lever of the ordinary Corliss valve-gear, which is connected by an adjustable rod with the plunger of the dash-pot. It is fixed upon the outer end of the valve-stem H and is formed with a recessed hub which fits over and bears upon the outer end of the extension j of the bonnet, thus relieving the valve-stem of lateral strain.

L is acylinder mounted upon the bonnet J transversely to the valve-stem. It is formed or provided on one side with a plate or collar l, which is bored out to fit over a circular boss on the flange or shoulder j and is adjustably secured in place by a bolt Z, passing through a slot in said flange and threaded in the plate or' collar 1, as shown in Fig. 2. By

this means the cylinder L is capable of antending arm 71", of lever K by a piv0t-pin and block m, fitted to slide in a transverse groove or recess in said plunger. One end of the ICO plunger M is closed while the other end is open. N is a spiral spring inserted in the open end of said plunger and bearing at its inner end against a cross wall or partition of the plunger and at its outer end against an adjustable plate or block W, supported upon the end of a screw 01., threaded axially in the adjacent head of cylinder L. This spring tends to move and hold the plunger with yielding force toward the opposite end of said cylinder, and its tension may be varied as desired by means of the screw it. The end of the cylinder L next to the closed end of the plunger M forms or is provided with an aircushion which serves to arrest the movement of said plunger in that direction without shock to the valve-gear. Near this end of the cylinder it is formed with a series of lateral ports or openings 2*, which allow free ingress and egress of air when they are uncovered by the plunger, and consequently permit unchecked movement of said plunger up to that point toward the adjacent head of the cylinder. This head of the cylinder, which is preferably secured thereto by a screw-thread, as shown in Fig. 3, is formed with a chamber Z communicating with the cylinder through a port 1* and indirectly with the atmosphere through lateral ports or openings Z The opening of the port Z is regulated by the manually-adjustable valve 1, the stem of which is threaded in the outer wall of the chamber Z and is provided outside of said chamber with a head or hand-wheel Z having in its back a series of depressions, as shown in Fig. 6, arranged to be engaged by a' spring-pin Z loosely held in a socket in the cylinder-head parallel with the stem of said valve Z as shown in Fig. 3. the valve Z can be readily and nicely adjusted and when adjusted will be held in place to produce any desired amount of cushion for the plunger M. This cylinder-head is also formed with a flange or extension fitting over the end of the cylinder and forming an an nular passage Z in communication with the ports V.

Z is a detachable cap or cover fitted over the cylinder-head and forming an annular passage around the chamber Z This passage communicates with said chamber through the ports Z and also with the passage 1 through openings Z. A pipe Z leads out of the cap or cover Z to the atmosphere at any convenient point. By this means the air entering or escaping from the ports Z and Z is conducted from or to a suitable point ofintake and discharge, where it will be free from dust and dirt, and the noise which it'would otherwise make is prevented or mufiied. The end of the cylinder L opposite the air-cushion may be made detachable, as shownin Fig. 3, to a-ftord access to the plunger and its actuating spring and to facilitate their removal. The extension of the cylinder-headin which the chamber Z is formed may be made polygonal, as shown in Fig. 5, to receive a wrench for screwing it on or ofi? from the cylinder.

The depending arm it of the lever K is provided on the inner side with a latchbloclc 10 O is the valve -opening lever-arm, corresponding in function with the steam-arm of the ordinary Corliss valve-gear. Itis formed with a hub or sleeve which is fitted to turn loosely on the extension j of the bonnet concentrically with the valve-stem 1-1. It is provided on its outer face with a latch-hook 0, which is pivoted thereto in position to be engaged with the latch-block for opening the steam-valve. The hook ohas an arm 0, held in engagement with the cut-oft cam P by a spring 0 as shown in Fig, 4. The cut-oft cam P is fitted to turn on the extension j of the bonnet between the lever K and leverarm 0 and is formed with oppositely-projecting arms 1919,130 which is attached an arch or curved bar 1). This arch is offset from the cut-cit cam by studs or bolts, as indicated by dotted lines in Fig. 2, and passes outside of the lever-arm 7t, concentric with the valvestem H.- The pin 0 to which the spring 0 is attached, serves as a stop to hold the latchhookin position to pass under and engage with the latch-block k The arch p affords means of connecting either one of the governor-rods g thereto at the most convenient and advantageous point, as shown in Fig. 7, without interfering with other parts of the valve-gear.

In half-stroke cut-01f engines the leverarms 0 O are extended, as shown in Figs. 1 and 2, for the attachment thereto of the rods ff, through which the exhaust-valves are "operated. By the means last described In Fig. 1 the valvegear is shown by full lines in its middle positionthat is, when the steam-valve is partially open-and by dotted lines in one extreme position,the valves beingclosed and the lever-arm O withdrawn to the full limit of its movement, the other extreme position of the lever-arms being indicated by dotted lines and points designating the pivot connections of said levers.

The steam valve gear hereinbefore described operates as follows: The steam-valve being closed and the lever K standing normally in the position indicated by dotted lines in Fig. 1, with its upper arm It turned to the extreme right and its lower arm is to the left, the lever-arm O, swung by the eccentric D from its extreme position at the right to its extreme position at the left, causes the hook o to pass under and engage with the latch-block k on the lever K. As the arm 0 swings back to the right it carries the level K with it, turning its upper arm in to the left, opening the valve and moving the plunger M against the tension of spring N to the left until the arm 0 of the hook engages the cam P, whereupon the hook is disengaged from the latch-block 74: and the lever K is released. When this occurs, the spring N will instantly move the plunger M back to the right, thereby closing the valve. As the closed end of the plunger passes over and closes the ports Z its movement will be checked by the air entrapped in the end of the cylinder L without shock or jar to the mechanism. The air escaping through the ports i into the passage Z and thence through the openings Z into the cap or cover Z and the air escaping from the ports Z into the chamber Z and thence through the ports Z into said cover Z is conducted noiselessly away to the atmosphere through the pipe Z The hook owill be disengaged from the trip-block k and the lever K will be released, allowing the valve to close sooner or later, according to the position of the cam P, which is controlled by the govern or. i

The construction and arrangement of the valve-gear, as shown in the drawings and hereinbefore described, dispenses with the adjustable rods by which the drop-arms of the ordinary Corliss valve-gear are connected with the plungers of the dash-pots, and the use of which is objectionable, because they are subject to vibration, especially in large or high-speed engines, and are very apt to get out of adjustment by the looseningof the jam-nuts caused by such vibration. These longadjustable dash-pot rods are also more or-less in the way and exposed to injury and accidents are liable to occur from their injury or improper adjustment. The usual wristplate connection for operating the valves is also dispensed with, the valve-operating gear of the several valves having a direct eccentric connection. I

Referring to Fig. 8, illustrating a modification of the eccentric connections of the valvegear, the steain-valves and the exhaust-valves are operated by separate eccentrics. D designates the additional eccentric for operating the exhaust-valves. It is connected by a rod dwith a rocker-arm E, which in turn is connected by a rod 6 with a wrist-plate Q, the latter being connected by rods q q with the arms F F on the stems of the exhaust-valves. In this case the eccentric D is connected by a rod 61 with a rocker-arm E fulcrumed to the engi ne-fra me concentrically with the arm E, and connected by a rod 6 with the leverarm 0 of the nearest steam-valve gear. The extension of the lever-arms 0 (shown in Fig. 7) for operating the exhaust-valves is omitted; but in other respects the steam-valve gear is the same as that hereinbefore described, and shown in Figs. 1 to 7, inclusive.

The rocker-arms E, E, and E are employed to avoid the necessity of long connecting-rods between the eccentrics and the valve-gearin1- mediately associated with the several valves, such long rods being objectionable, particularly in large engines or engines that are runat a high speed, on account of their tendency to vibrate and liability to be bent and inj ured. These rocker-arms also admit of the use of smaller eccentrics.

In the place of the springsN for closing the steam-valves other means may be employed such, for example, as fiuid-pressureand in place of the sliding pivot-block connection between the lever-arm 7t and the plungers M short links or other connections may be used. In short, various modifications in the details of construction and arrangement of parts may and means constantly tending to move said plunger into and hold it in position for closing the valve, substantially as and for the purposes set forth.

2. The combination with a valve-stem and a bonnet, of an arm fixed upon said stem, a cylinder mounted upon and supported by said bonnet transversely to said stem and capable of angular adjustment on said bonnet about said valve-stem, a plunger fitted to work in said cylinder and connected with said stem, and means tending to move said plunger into and to hold it in position for closing I the valve, substantially as and for the purposes set forth.

3. The combination with a valve-stem and a bonnet having a cylindrical extension through which said stem projects, of a valveoperating arm fixed upon the projecting end of said stem and having a recessed hub fitted over and adapted'to turn on the cylindrical end of said bonnet, whereby the stem is relieved of lateral strain, substantially as and for the purposes set forth.

4. The combination with a valvestem and a bonnet having a cylindrical extension and a flange or shoulder, of a cylinder having a plate in a plane parallel with its axis fitted upon the cylindrical extension against said flange or shoulder and adjustably attached thereto, a valve-stem passing axially through the, extension of said bonnet and provided with an arm fixed thereon, and a plunger fitted in said cylinder and connected with said arm, substantially as and for the purposes set forth.

5. The combination with a valve-stem having an arm fixed thereon and a bonnet through which said stem projects, of a cylinder mounted upon and supported by said bonnet transversely to the valve-stem and having a side opening, a plunger fitted in said cylinder and having a transverse recess in one side next to the side opening in the cylinder, and a pivotblock fitted to slide in said recess and engaged by a pin on said arm, substantially as and for the purposes set forth.

6. The combination with a valve-stem provided with an arm fixed thereon and a bonnet through which said stem projects, of a cylinder mounted on said bonnet transversely to the valve-stem and having a side opening, a port in one end and a lateral port near the same end both communicating with the atmosphere, a manually-adjustable valve for regulating the area of opening through the port in the end of said cylinder, a plunger fitted in said cylinder and connected through the side opening therein with the arm on the valve-stem, and means tending to move and hold said plunger toward the ported end of said cylinder, substantially as and for the purposes set forth.

7. The combination with a valve-stem provided with an arm, of a cylinder arranged transversely to and in close proximity with said valve-stem and provided at one end with a headhaving a chambercommunicating with the cylinder through a port and through one or more lateral openings with a passage leading to the atmosphere, said cylinder having near its ported head one or more lateral openings which also communicate with said passage; a valve for adjusting the port-opening in said cylinderhead, having its stem threadt ed in the on ter wall of said head and provided with a hand-wheel which has a circular series of recesses in the back adapted to be engaged by a spring-pin held in a socket in the cylinder-head parallel with the stem of said regulating-valve; aplunger fitted in said cylinder and connected on one side with the arm on the valve-stem through an opening in one side of said cylinder; and means tending to move and hold said plunger toward the ported end of said cylinder, substantially as and for the purposes set forth.

8. The combination with a valve-stem provided with an arm, of a cylinder arranged transversely to and in proximity with said valve-stem and provided at one end with an adjustable muffled air-cushion comprising a head formed with a chamber which communicates with the cylinder through a port and has a recessed flange or extension fitting over 1 the end of said cylinder and forming therewith an annular passage communicating with 1 the interior of the cylinder through a number i of lateral openings therein; a manually-adjustable valve controlling the port between said cylinder and the chamber in its head; a cap or cover forming an annular passage around said head in communication with the chamber and annular passage therein and having a connection leading to the atmosphere; and a plunger fitted in said cylinder and connected with the arm on said valvestem, substantially as and for the purposes set closing arm a cut-ofi cam mounted and fitted to turn on said bonnet and an arch attached to said cam by arms and connected with the governor, substantially as and for the purposes set forth. 4

10. The combination with a valve-stem and a bonnet having a cylindrical extension through which said stem projects; a cylinder mounted on said bonnet transversely to said stem; a plunger fitted in said cylinder; a lever fixed upon the projecting end of the valvestem and having one arm connected with one side of said plunger and another arm pro vided with a latch-block; an arm or lever loosely mounted on said bonnet, connected with the eccentric and provided with a latch- .hook adapted to be engaged with said latchblock; and a cut-off cam having a governor connection and adapted to disengage said book from said latch-block, substantially as and for the purposes set forth.

11. The combination with a valve-stem pro-- vided with a lever fixed thereon, of a cylinder arranged transversely to said valve-stem; a plunger fitted in said cylinder and connected on one side with said lever; an independentlymovable lever-arm fulcrumed concentrically with the valve-stem; a latch pivoted to said lever-arm and adapted to be engaged with the lever on the valve-stem; and a cut-off cam having agovernor connection and adapted to disengage said hook from said lever, substantially as and for the purposes set forth.

12. The combination with a rocking valvestem and a bonnet through which said stein projects, of a lever fixed upon said stem; a

cylinder arranged transversely to said valvestem 5 a plunger fitted in said cylinder and connected at one side with said lever; a le ver-arm loosely mounted on said bonnet and provided with a latch-hook which is adapted to be engaged with the lever on the Valvestem for opening the valve; and a cam also loosely mounted on said bonnet between said lever and arm and provided with an offset arch passing outside of said lever and serving for the attachment of the governor connection, substantially as and for the purposes set forth.

13. The combination with an oscillating valve-stem and a bonnet through which it projects, of a cylinder mounted upon said bonnet transversely to the valve-stem and capable of angular adjustment about the axis of the valve-stem; a plunger fitted in said cylinder; a lever fixed upon said valve-stem and connected with said plunger; a lever-arm mounted loosely upon said bonnet and provided with a pivoted latch-hook adapted to engage with said lever for opening thevalve; and a cam also loosely mounted upon said bonnet between said lever and arm and having a governor connection for disengaging the hook from said lever; substantially as and for the purposes set forth.

14:. The combination with an oscillating valve-stem and a bonnet through which it IOo e54,22s t projects, of a cylinder mounted upon said bonnet transversely to said stem; a plunger fitted in said cylinder; a lever fixed upon the valve-stem and connected with said plunger; a valve-opening arm loosely mounted on said bonnet and provided with a latch-hook pivoted thereto; a cam also loosely mounted on said bonnet between said lever and arm and provided with an arch passing outside of said lever concentric with the valvestem; and a spring holding said vhook in position for engagement With said cam; substantially as and for the purposes set forth.

15. The combination with an oscillating valve-stem and a bonnet having a cylindrical extension through which said stem loosely passes, of a cylinder mounted upon said bonnet transversely to said valve-stem and capable of angular adjustment about the valvestem as an axis; a plunger fitted in said cyl, inder; a lever fixed upon the projecting end of said valve-stem, having a bearing upon the bonnet and connected on one side of said stem with said plunger and provided on the opposite side of the valve-stem with a latchblock; a. lever-arm loosely mounted upon said bonnet and provided with a latch-hook pivoted thereto and adapted to engage with the latch-block of said lever for opening the valve; a cam loosely mounted upon said bonnet between said lever and arm and provided with an oifset curved bar, passing outside of said 1 lever concentric with the valve-stem, for the attachment of the governor connection; and a spring tending to hold said latch-hook in position for engagement with said cam; substantially as and for the purposes set forth.

16. The combination with the steam-valves of an engine, of cylinders arranged transversely to and in proximity with the valve stems; plungers fitted in said cylinders for closing said valves; levers fixed on the valvestems and connected with said plungers; independently-movable arms fulcrumed con,- centrically with said levers, provided with latch-hooks for engaging said levers and opening the valves and having direct connection with the eccentric; and cams connected with the governor for disengaging said hooks from said levers, substantially as and for the purposes set forth.

17. The combination with the steam and exhaust valves of an engine, of cylinders arranged transversely to and in proximity with the steam-valve stems; plungers fitted to work in said cylinders; levers fixed upon the steamvalve stems and connected with said plungers for closing said valves; independentlymovable arms fulcrumed concentrically with said levers and provided with pivoted latchhooks which are adapted to engage with said levers for opening the steam-valves; cams connected with the governor for disengaging said hooks from said levers; arms fixed on the exhaust-valve stems and connected by rods with the valve-opening arms of the steam-valve gear; and a rod connecting said valve-opening arms, one'of which is directly connected With the eccentric-rod; substantially as and for the purposes set forth.

18. The combination with the steam-valves, eccentric and eccentric-rod, of valve-closing levers fixed 011 the stems of said valves; independently movable arms provided with latch-hooks for engaging said levers and opening the valves, said arms being directly connected with each other by a rod and one of them being directly connected with the cocentric-rod, and oamsconnected with the governor for disengaging said hooks from said levers, substantially as and for the purposes set forth.

19. The combination with the steam and exhaust valves and an eccentric and eccentric-rod for operating the same, of valve-closing levers fixed upon the steam-valve stems; independently-movable arms provided with latch-hooks for opening the steam-valves by engagement with said levers cams connected with the governor for disengaging said hooks from said levers; arms mounted on the exhaust-valve stems and connected by rods with the valve-opening arms of the steam-valves; and a rod connecting said valve opening arms, one of which is directly connected with the eccentric-rod, substantially as and for the purposes set forth.

In witness whereof I hereto afiix my signature in presence of two Witnesses.

NIELS A. CHRISTENSEN.

Witnesses:

OHAs. L. Goss, M. L. EMERY. 

